Tools with a gripping or cutting function such as, for example, scissors or forceps are used in many areas. As a rule, said tools consist of two parts which are connected together by means of a screw. If said two parts need to be cleaned, which among other things is necessary in medical application, the screw has to be undone. In addition, the surgical instrument has to meet the demands of the operation. The instrument, in particular surgical forceps, has to be sturdy, functional and easy to handle. In addition, it should have a resilient end position in order to limit the force onto the held objects. Part of the easy handling is the rapid and simple dismantling of the surgical instrument. This is necessary so that the surgical instrument is able to be disinfected and cleaned in an autoclave.
The usual design of surgical scissors or forceps includes many small parts, the forceps parts being held together by screw or pin connections. Prior to disinfection and cleaning, the instrument has to be taken apart laboriously. After disinfection and cleaning the surgical instrument has to be put back together again laboriously. If small parts are lost, assembly is no longer possible and the instrument is no longer available for the next operation. For this reason tools have been developed which are easily able to be broken down into their individual parts. Said tools include two individual parts which are releasable without a further tool.
U.S. Pat. No. 2,632,661 discloses a pivot joint for a pair of scissors or forceps, one pivot part including a guide rail which is able to be coupled into a guide groove of the other pivot part. The coupling of the two pivot parts is only possible with the joint at a certain angle of opening. At said angle of opening, the guide rails of the one pivot part are no longer encompassed by the guide groove of the other pivot joint, the two pivot parts being able to be released in said position. The disadvantage of said apparatus is that the guide grooves are only able to be cleaned in a very poor manner as they are very deep and narrow. Thus, for example, tissue parts or tissue fluids are able to be deposited in said grooves such that bacteria and viruses are able to reproduce there or said bacteria and viruses are not able to be killed off even in a disinfecting autoclave. In addition, said apparatus has the disadvantage that when opened wide, the two pivot parts are unintentionally uncoupled. This makes the handling of the tool more difficult and can also provide a safety risk in the case of surgical interventions.
U.S. Pat. No. 5,197,879 discloses a pivot joint for scissor-like tools in the medical area which consists of two identically formed halves. Each half includes a guide recess and a guide rail, in the coupled state the guide rail of the one part engaging in the guide groove of the other part. The pivot joint can be uncoupled in a certain position of opening, the guide rails in said position of opening no longer engaging in the guide grooves. The disadvantage of said apparatus is that it can also result in unintentional uncoupling when opened wide.